US7263234B2 - System and method for video encoding according to degree of macroblock distortion - Google Patents

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• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
  • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
  • H04N19/134—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or criterion affecting or controlling the adaptive coding
  • H04N19/154—Measured or subjectively estimated visual quality after decoding, e.g. measurement of distortion
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
  • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
  • H04N19/102—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or selection affected or controlled by the adaptive coding
  • H04N19/115—Selection of the code volume for a coding unit prior to coding
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
  • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
  • H04N19/169—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding
  • H04N19/17—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding the unit being an image region, e.g. an object
  • H04N19/176—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding the unit being an image region, e.g. an object the region being a block, e.g. a macroblock
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
  • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
  • H04N19/189—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the adaptation method, adaptation tool or adaptation type used for the adaptive coding
  • H04N19/196—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the adaptation method, adaptation tool or adaptation type used for the adaptive coding being specially adapted for the computation of encoding parameters, e.g. by averaging previously computed encoding parameters
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
  • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
  • H04N19/189—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the adaptation method, adaptation tool or adaptation type used for the adaptive coding
  • H04N19/196—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the adaptation method, adaptation tool or adaptation type used for the adaptive coding being specially adapted for the computation of encoding parameters, e.g. by averaging previously computed encoding parameters
  • H04N19/197—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the adaptation method, adaptation tool or adaptation type used for the adaptive coding being specially adapted for the computation of encoding parameters, e.g. by averaging previously computed encoding parameters including determination of the initial value of an encoding parameter
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
  • H04N19/50—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding
  • H04N19/593—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding involving spatial prediction techniques
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
  • H04N19/60—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using transform coding
  • H04N19/61—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using transform coding in combination with predictive coding

Definitions

• the present invention relates to a video image encoding method, and more particularly, a method of encoding according to the degree of macroblock distortion.
• a digital video can be looked as a series of static digital image. Under a continuous playing situation, because the sense of the sight temporary stop, can regard as a continuous video.
• the digital image comprises a plurality of macroblocks. Without compression, the digital video usually needs a lot of storing space and bandwidth.
• Another prior art based on the complex of the macroblock proceed the bit budget distributing.
• the complex of the macroblock can not respond to the digital image quality.
• the method based on the complex of the macroblock distributing cannot distribute bit budget efficiently yet.
• an objective of the invention is to provide a method for video encoding according to the degree of macroblock distortion, by using bit rate efficiently, to increase the compressed image quality.
• the video encoding method of the present invention distributes the bit rate to a target macroblock in a digital image.
• the digital image comprises a plurality of macroblocks, and each macroblock performs the further video image encoding according to the distributed bit rate.
• the comparison area includes a plurality of macroblocks that have already been distributed the corresponding bit rates.
• SMC Similar Macroblock Choosing
• VDC Video Distortion Calculation
• the present invention can distribute the bit rate efficiently, and precisely distribute the bit budget in every macroblock. After decompressing the digital image, the digital image can get better image effect.
• FIG. 1 is a schematic diagram of the digital image of the video encoding method and system according to the present invention.
• FIG. 2 is a function block diagram of the video encoding system according to the present invention.
• FIG. 3 is a function block diagram of the quantization scaling controller shown in FIG. 2 .
• FIG. 4 is a schematic diagram of choosing a comparison area according to the target macroblock shown in FIG. 1 .
• FIG. 5 is a schematic diagram of choosing a similar macroblock from the comparison area shown in FIG. 4 .
• FIG. 6 is a flow chart of the video encoding method according to the present invention.
• FIG. 1 is a schematic diagram of the digital image 10 of the video encoding method and system according to the present invention.
• the digital image 10 comprises a plurality of macroblocks 11 .
• Each macroblock 11 is a square and has 16 pixels 14 in the length and in the width, so each macroblock has 256 pixels 14 .
• Each pixel 14 has an original gray level.
• the video image encoding method according to the present invention is for distributing a bit rate to a macroblock 11 in a digital image 10 while performing the video image encoding.
• Each macroblock 11 performs further the video image encoding according to the distributed bit rate.
• the following illustration showing the video encoding method of the present invention is for a macroblock in the digital image 10 to describe. Here we call a target macroblock 12 .
• FIG. 2 is a function block diagram of the video encoding system 18 according to the present invention.
• the encoding system 18 according to the present invention comprises a Discrete Cosine Transform (DCT) module 24 , a qunatization scaling module 22 , a qunatization scaling controller 20 , an Inverse Discrete Cosine Transform (IDCT) module 26 , and an inverse qunatization scaling module 28 .
• DCT Discrete Cosine Transform
• IDC Inverse Discrete Cosine Transform
• the DCT module 24 is for processing a DCT procedure on each macroblock, and then each macroblock becomes a DC format.
• the DC format is to display an image data in a frequency domain.
• the quantization scaling module 22 scales down the obtained values by a predetermined quantization scale and to reduce the associated bit rate, for further generating a corresponding MPEG compressed video image.
• the quantization scaling controller 20 changes the predetermined quantization scale.
• the inverse quantization scaling module 28 inverses the process of the quantization scaling module 22 .
• the IDCT module 26 performs an IDCT procedure on the compressed video image so as to reconstruct a corresponding reconstruction macroblock.
• the reconstruction macroblock includes the same numbers of pixels 14 as the original (before compressed) macroblock does, and each pixel 14 in the reconstruction macroblock has a corresponding reconstruction gray level.
• FIG. 3 is a function block diagram of the quantization scaling controller 20 shown in FIG. 2 .
• the quantization scaling controller 20 according to the present invention comprises a comparison area choosing module 30 , a similar macroblock choosing module 32 , a distortion calculation module 34 , and a bit rate determination module 36 .
• the comparison area choosing module 30 is used for choosing a comparison area 16 according to the location of the target macroblock 12 in the digital image 10 .
• the similar macroblock choosing module 32 is used for choosing a similar macroblock from the macroblocks 11 of the chosen comparison area 16 .
• the distortion calculation module 34 is used for calculating respectively a first video distortion variable R_avg and a second video distortion variable R_sml.
• the bit rate determination module 36 is used for determining the bit rate of the target macroblock 12 .
• FIG. 4 is a schematic diagram of choosing a comparison area 16 according to the target macroblock 12 shown in FIG. 1 .
• the comparison area chosen process according to the present invention is that the comparison area choosing module 30 basing the center on the target macroblock 12 defines the plurality of adjacent macroblocks, which have already been distributed the corresponding bit rates, as the comparison area 16 . So the comparison area 16 comprises a plurality of macroblocks 11 that have already been distributed the corresponding bit rates.
• the area marked by the oblique lines in FIG. 4 is the comparison area 16 .
• FIG. 5 is a schematic diagram of choosing a similar macroblock from the comparison area 16 shown in FIG. 4 .
• the present invention has a Similar Macroblock Choosing (SMC) procedure.
• SMC Similar Macroblock Choosing
• the similar macroblock choosing module 32 calculates the total sum of the original gray levels of all the pixels 14 within the target macroblock 12 . Because the gray level that the target macroblock 12 has 255 pixels 14 is 2, only one gray level of the pixel 14 is 3, the total and the target original gray level are all 513.
• the similar macroblock choosing module 32 respectively calculates the total sum of the original gray levels of all the pixels 14 of macroblock 40 , 42 , 44 and 46 in the comparison area 16 to generate the comparison original gray levels 515 , 617 , 103 , and 402 respectively. Then, the similar macroblock choosing module 32 respectively compares the comparison original gray levels with the target original gray level to pick out the macroblock with the smallest difference as the macroblock 40 , so the similar macroblock choosing module 32 defines the macroblock 40 as the similar macroblock of the target macroblock 12 .
• the calculation method of the first video distortion variable R_avg is performed a distortion calculating process by the distortion calculation module 34 .
• the first video distortion variable R_avg means the average degree of distortion in the comparison area 16 .
• the second video distortion variable R_sml is the similar macroblock video distortion variable corresponding to the target macroblock 12 .
• T_tar the bit rate distributed to the target macroblock 12
• K is an adjustable weight.
• the adjustable weight k is the experience value by the experiment, and proportional to the bit rate.
• the method of determining the target macroblock 12 the distributed bit rate according to the present invention is performed a bit rate determining process by the bit rate determination module 36 .
• the distributed bit rate T_sml of the similar macroblock adds up the difference between the first video distortion variable R_avg and the second video distortion variable R_sml.
• the sum is multiplied by the adjustable weight k to determine the bit rate of the target macroblock 12 .
• FIG. 6 is a flow chart of the video encoding method according to the present invention.
• the video encoding method according to the present invention when distributing the video image encoding bit rate of the target macroblock 12 in the digital image 10 , comprise the following steps:
• Step S 52 choosing a comparison area 16 in the digital image 10 according to the location of the target macroblock 12 .
• Step S 54 choosing a similar macroblock from the comparison area 16 according to the SMC procedure.
• Step S 56 calculating respectively the first video distortion variable R_avg and the second video distortion variable R_sml according to the VDC process.
• Step S 58 determining the bit rate of the target macroblock 12 by the formulas according to the distributed bit rate T_sml of the similar macroblock, the first video distortion variable R_avg, the second video distortion variable R_sml and the adjustable weight k.
• the bit rate distributing method according to the present invention can get a better digital image effect after decompressing the digital image 10 .
• the present invention can more correctly distribute the bit budget.

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Citations (7)

• 2002
  • 2002-11-13 TW TW91133304A patent/TWI220636B/en not_active IP Right Cessation
• 2003
  • 2003-11-12 JP JP2003382403A patent/JP2004289790A/en active Pending
  • 2003-11-12 US US10/704,629 patent/US7263234B2/en not_active Expired - Fee Related

Patent Citations (7)

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